Injuries to soft tissues, such as skin, muscle, connective tissue, or vascular tissue, are common occurrences. In some instances, minor soft tissue injuries are able to self-repair without any outside intervention, but frequently the extent of an injury is severe enough, or the capacity of the soft tissue to self-repair is limited enough, that surgical intervention is required. Surgery to repair a soft tissue injury generally entails implanting or applying a biocompatible material that is meant to replace the missing or defective tissue (for example, using a graft to replace a torn tendon or ligament). However, even with surgical intervention, the process of repairing or reconstructing the injured soft tissue can be slow or incomplete.
Stem cells have been shown to be useful in promoting wound healing and the repair of injuries to soft tissues such as tendons and ligaments. See, e.g., Yin et al., Expert Opin. Biol. Ther. 10:689-700 (2010); Hanson et al., Plast. Reconstr. Surg. 125:510-6 (2010); and Cha and Falanga, Clin. Dermatol. 25:73-8 (2007). Stem cells have also been used to promote soft tissue reconstruction, for example using stem cell-seeded small intestinal submucosa to promote bladder reconstitution and meniscus reconstruction. Chung et al., J. Urol. 174:353-9 (2005); Tan et al., Tissue Eng. Part A 16:67-79 (2010).